Fitness equipment superstructures, also referred to as “rack and rig” systems, are in general known in the art. Examples are shown in U.S. Pat. Nos. 4,657,246, D635,206, D636,038, D636,039 and D636,040, U.S. Patent Pub. No 2013/0065738 and U.S. patent application Ser. No. 14/327,319, all incorporated by reference. These systems are mainly for and used in cross fit gyms, pull up rigs, and other athletic/exercise facilities.
One of the basic components is the columns or uprights used in constructing the superstructure. Generally speaking, each upright is constructed from a steel (or other strong metal) tube, such as a 2×2, 2×3 or 3×3 inch rectangular tube, which has a number of holes formed along its length. These tubes typically have about an 8 or a 9 foot length, with the tube welded at one of its ends to a flat base plate. The flat base plate typically includes bolt holes (such as four per upright/base plate) for bolting to the floor. The holes along the length of the upright are for attaching cross-member bars, J-cups and other accessories and hardware.
Separate from the uprights used in fitness equipment superstructures but in the field of fitness equipment, other fitness equipment commonly has uprights which are constructed to be adjustable in height, such as in the weight bench of U.S. Pat. No. 4,765,616. A common way to make adjustable height uprights is to use telescoping tubes, having a series of through-holes along one or both of the tubes' lengths, with a pin which is placed into aligned through-holes to hold the telescoping tubes relative to each other. One shortcoming of telescoping tubes of such structures is that one of the telescoping tubes is smaller in width (to fit within the wider tube), and therefore weaker (assuming the same wall thickness). To be able to support significant weight with the smaller tube, often the larger tube is over-designed, i.e., bigger, stronger, heavier and more costly than necessary.
Outside the fitness equipment field entirely, other structures have uprights which are required to be transportable and therefore are designed for ease of assembly and disassembly, such as the uprights used in tents. To allow tubular uprights to be shorter during transport, often the uprights include a short telescoping section which is either wider or narrower than the mating end of the adjacent tube section. During assembly, the narrower end of one tube is inserted into the wider end of the attaching tube. However, such other structures often are not required to support the vertical and bending loads which are placed on fitness equipment superstructures. Significant vertical overloads on such assembled uprights can cause the smaller end to wedge too tightly into the larger adjacent tube, causing damage or making disassembly difficult or impossible. This type of “telescoping end” construction has accordingly not found favor in fitness equipment superstructures.
Instead, fitness equipment superstructures have remained with long—often 8 or 9 foot—uprights of single piece construction. Such long uprights, though functional in use, are difficult to transport, being both heavy and longer than many vehicle beds. The long uprights are also expensive, and it is often difficult and costly to replace a long upright should one become damaged. Better solutions are needed.